HI Dave,
Probably you're talking about Hydroponics System. You should specify what crops you're suppose to plant. Every crop has its own specific food nutrients requirement.
Hydroponics system is a delicate method to apply, because it needs a skilled person to operate the system. However, there are some of the methods that are easy to manage, but you need trainings to catch up how it operates.
You can buy some training kits in your area about hydroponics gardening tips.
I hope this helps your problem.
Happy gardening!
Cris
www.crisramasasa.com